Anybody seen this before?

Ok, for the past few weeks the main stem has been splitting, not on purpose. I have tipped it a few times and also training it. As soon as i saw the split i slacked of all the ties hoping it would heal itself. not the case. Since the splitting, the buds attached to the stems above the split are getting wierd little yellow spots on the leaves and the buds are gettin brown patches( looks as if its slowly dying.)
Its in soil feeding it dutch master nutes ph 6.9 and 4 weeks into bud. 400w hps light.

Any help or advice needed.

Was thinking of chopping the whole split out, so it doesnt increase further down, as it looks as if its getting deeper.

Only a few pics, cant get one dirctly down as to much folige and bud in the way. Hope these pics help.

I'm sorry I can't really tell what you're talking about....the pic is a little blurry. That is a VERY NICE plant you have there... :thumbsup:

If it is something affecting the leaves above....I'd cut it off and make sure you cut it at a healthy spot well below the damaged area.. ;)

you have a potassium def. which is also the cause of the brittle splitting stems

You're training WAY too aggressively. Duct tape. NOW.
Untie the stems that are above the split, tape the split so it doesn't get worse, and make sure your fertilizer has adequate potassium- it is important for the plant's immune system, to prevent disease from taking hold.

and get a better camera